How well can European radars detect supercells and tornadoes?

As more European weather services release their single-site volumetric radar data as open data, ESSL has integrated a large number of these radar sites into a unified viewer. This tool enables the monitoring of convective storm activity across a broad region of Europe, including countries such as France, the Netherlands, Germany, Denmark, Czechia, Austria (partially), Poland, Romania, Estonia, and Finland.

The web-based interface offers intuitive functionality, allowing users to zoom in and out, switch between radar sites, change scan elevation, and easily navigate through time. It also provides seamless switching between various radar parameters, including reflectivity (Z), radial velocity (V), correlation coefficient (CC), differential reflectivity (ZDR), and, for some radars, specific differential phase (KDP). A promising method for identifying (large) hail involves the use of an RGB composite image, where reflectivity, correlation coefficient, and differential reflectivity are represented by the red, green, and blue channels, respectively.

Using several case studies involving strong supercells, both tornadic and non-tornadic, we analyzed how effectively mesocyclones and tornadic rotation can be identified. The results highlight the influence of radar configurations, primarily C-band, across different countries. Key factors affecting detection include the use of dual- or triple-PRF (Pulse Repetition Frequency), which extends the Nyquist velocity range, as well as the extent of velocity data filtering. Other relevant factors include scan update intervals, gate length, beamwidth, and scanning strategies.